Line marking devices known in the art typically comprise of a spool on which a string is wound under tension. The string is extended through a marking dye reservoir such as chalk or ink and snapped onto the desired location to mark a line. A clip or hook attached to the extending end of the string opposite to the spool may be used for gripping the line when extending it out of the spool and to prevent the end of line from being pulled into the spool when released.
U.S. Pat. No. 4,551,922 provides for a line marking device comprising an extensible pipe assembly, a pair of arm members pivoted to the opposite ends of the pipe assembly, two reels rotatably supported on the pipe assembly between the opposite ends of the pipe assembly, an ink pad assembly mounted on one of the arm members, guide wheels rotatably supported on the arm members, a line marking string anchored at the opposite ends to the reels and guided along the guide wheels and a spirit level mounted on the pipe assembly between one of the arm members and one of the reels.
U.S. Pat. No. 4,765,557 is directed to an automatic retractable chalk snap string device having an improved brake structure for selectively braking the spring-biased hub on which the chalk string is retractably wound.
U.S. Pat. No. 5,042,159 discloses a chalk line retraction device formed of a hollow casing defining a chalk line aperture there through. A chalk line reel carrying a chalk line is mounted for rotation within the casing and is keyed to a spur gear. The spur gear is engaged with a ring gear of much larger pitch diameter.
U.S. Pat. No. 5,920,997 is for an automatically retractable chalk line device having a housing in which a power spring drives a first large diameter gear through a first shaft. The first large diameter gear is in driving engagement with a first smaller diameter gear located below the power spring. The first smaller diameter gear drives a second large diameter gear located partially above the power spring. The second large diameter gear drives a second smaller diameter gear which a drives a chalk retaining spool, which holds the chalk line.
U.S. Pat. No. 6,470,581 describes a dual chalk line marker device having two chalk line spools that are adjustably movable with respect to the housing or base. The spools are adjustable in order to vary the separation width between the chalk lines so that different widths of joist or roofing shingle can be properly marked for disposition upon a work surface.
Embodiments similar to that of the present invention are described in U.S. Pat. No. 7,908,754 for a dual level marking apparatus that enables a single worker to snap a marking line comprised of: a substantially linear housing forming at least one substantially planar surface comprised of a square tubular body, and at least one internal channel parallelly positioned to the substantially linear housing; a reservoir containing a marking material secured to at least one surface of the housing; at least two pulley components parallelly positioned at opposite ends of said housing; at least one tension control component having at least one tension adjustment control adapted to manipulate at least one of said at least two pulley components, at least one horizontal level bubble parallelly positioned within the substantially linear housing; at least one vertical level bubble perpendicularly positioned within the substantially linear housing; a line with no loose ends adapted to receive said marking material secured to each of at least two pulley components as a continuous loop and mounted to move slidably through the reservoir parallel with the housing. In a preferred embodiment, a housing includes at least one internal channel which may be hollow or partially hollow or contain apertures or recesses for depositing one or more marking material reservoir.
In other embodiments, more or fewer spool components may be utilized, and spool components may be of different shapes and configurations, or internally or externally mounted. In the embodiments shown, spool component may further include a pivotal handle which allows the user to rotate the spool component but other embodiments may include functional equivalents such as a knob, lever, protuberance or other structures.